Shock absorbing marine berthing device



June 14, '1938.

SHOCK ABSOHBING MARINE BERTHING DEVICE Filed Jan; 25, less s Sheets-Shee 2 E. J. BUCKTON 2,120,545

June 1938. E. J. BUCKTON SHOCK ABSORBING MARINE BERTHING DEVICE Filed Jan. 23, 1936 3 Sheets-Sheet 3 .2 i: L 1 a WM l J v m r .r 9 n I H%H. .HHHH w r x M m 4 m .n 2 m M 1 u \2 4 1 m t Mr innuuwwmnwnnnuul LN w! rllllllllllL Patented June 14, 1938 PATENT FFHQE SHOCK ABSORBING MARINE BERTHING DEVICE Ernest James Buckton, London, England Application January 23, 1936, Serial No. 60,436 In Great Britain March 4, 1935 3 Claims.

This invention relates to devices for receiving the thrust of a ships side during berthing and like operations, and has for its object to provide a yielding device capable of arresting a slowly drifting or swinging ship without damage and with the minimum of shock and disturbance.

The invention accordingly consists in a bumper-buoy, fender, guard, water spring or like device for docks, floating wharves, mooring berths and the like, comprising a fender member and a buoyant member associated therewith, and means for so anchoring or pivotally mounting the members that lateral displacement of the fender member causes depression of the centre of buoyancy of the buoyant member, preferably relatively rapid depression thereof so as rapidly to absorb a large amount of energy. Preferably the members comprise a floating fender and a normally floating buoyancy chamber maintained in spaced relationship by a rigid connecting structure, in which case the fender may be anchored to a submerged point or points lying substantially in a vertical plane passing adjacent to the fender, and the buoyancy chamber to a submerged point or points in or adjacent to the said plane.

Thus, for example, the fender and the buoyancy chamber may each be provided with anchorage means comprising one or a set of chains or links, that for the fender lying in a substantially vertical plane so that the fender moves substantially horizontally on receiving a lateral thrust, and that for the buoyancy chamber lying generally in a plane at a high angle to the vertical so that the buoyancy chamber is sharply depressed on receiving said thrust from the fender through the rigid connecting structure.

Further features of the invention and their attendant advantages will be apparent from the following description and accompanying drawings, which have reference to certain of the many practical forms which the invention may take.

In the drawings:-

Figure 1 is a side elevational view of one form of bumper-buoy according to the invention, at the commencement of its operation.

Figure 2 is a plan view thereof,

Figure 3 is a view similar to Figure l, but showing the device in full operation,

Figures 4 and 5 are respectively a section and a longitudinal elevation of a self-draining dashpot form of buoyancy chamber,

Figure 6 is a plan view, on a reduced scale, of a mooring berth comprising three bumper-buoys in alignment,

Figure '7 is a plan view showing two bumperbuoys with their fender portions incorporating a common landing or mooring platform,

Figure 8 is a section thereof on an enlarged scale,

Figure 9 is a diagrammatic side elevation of a form of device adapted to be carried by a wharf, pier or the like,

Figure 10 is a plan view thereof,

Figure 11 is a view similar to Figure 9 but showing the device in place in a quay or jetty wall,

Figure 12 is a diagrammatic side elevation of a further modification of the invention, suitable for use on uays and like berths, and

Figure 13 is a plan view thereof.

The form of device shown in Figures 1 to 3 comprises a generally cylindrical floating fender member I and a long rectangular tank or buoyancy chamber 2 maintained in parallel spaced relationship by a rigid braced structure indicated generally at 3. The whole device is anchored to a single submerged point t in the following way:-

Two chains 5 are fastened at their upper ends to points in the structure 3 adjacent to the fender l and lying on a line parallel thereto. These chains converge downwardly and in a vertical plane, their junction being adjacent to the harbour bed at t, where they are anchored. Two further chains attached to spaced points on the buoyancy chamber 2 also converge towards point 4, and so lie in a very much inclined plane. Chains 5 are joined to form a single chain 1 which passes through an enlarged link at the junction of chains 5 and out along the harbour bed to an anchorage at 8.

Thus when as indicated in Figure 3, the side 9 of a ship bears against the fender l, the entire bumper-buoy device pivots about an axis passing through the point t and parallel to the ships side. Whereas, however, the fender l moves horizontally the buoyancy chamber 2, owing to the obliquity of its anchoring chains 6, is sharply depressed by the said pivotal movement, and so exerts a resilient restoring force in opposition to the momentum of the ship, bringing the latter to rest in a smooth and certain manner.

It is to be noted that owing to the plane of the chainsE being somewhat offset from the fender i, a ships side can deflect the bumperbuoy within reasonable limits without fouling them.

It is also to be noted that the resilient action of the buoy will continue until the buoyancy 55 chamber 2 touches bottom, this range being sufficient for all normal requirements. Should, however, the ship continue to bear down on the buoy after the chamber 2 becomes grounded, the buoy will act as a positive strut and may readily be made strong enough, at least in combination with its fellows, to arrest the ship safely in such an emergency.

It will further be observed that the fact that the buoy is in effect anchored at, or substantially at, the single point 4 permits it always to swing into alignment with a ships side coming into contact with the fender I. In order however, to keep such freedom within bounds when the buoy is idle, subsidiary lateral anchorage chains ill (see also Figure 6) may be used, such chains being of course relatively slack.

It may in some cases be desirable to ensure that when a ship has been brought to rest a minimum of stored energy remains in the bumper-buoys which, if appreciable, would tend gradually to push the ship away from its berth again, and with this in view a modified form of buoyancy chamber such as indicated in Figures 4 and 5 may be used.

This chamber is adapted gradually to lose some or all of its buoyancy on continued depression or submersion, and to this end it is divided up by internal watertight bulkheads in the following manner:-- 7

An approximately horizontal bulkhead i I is situated at or slightly above the normal water line, and the space above it is divided by vertical bulkheads l2 into a series of watertight compartments I 3. It will be observed that the bulkhead II has a slight slope so that each of the compartments l3 has a lowest point, at which, in the case of some of the compartments, is provided an opening or sea-cock l4.

Thus when the buoyancy chamber 2 is depressed or submerged, water will commence to enter such of the compartments as are provided with sea-cocks l4, air vents [5 being provided in the roofs thereof, and the chamber 2 gradually loses buoyancy.

The rate at which it does so is determined by the size and number of the floodable compartments and the eifective apertures of the seacocks I4 and air vents H3. The arrangement will of course be such that the minimum buoyancy will be normally reached when or shortly after the ship has been brought to rest, the buoy thus simultaneously absorbing and dissipating energy in the manner of a dashpot device. There will of course always remain a certain reserve buoyancy, due to the permanently sealed compartments, sufiicient when the lateral thrust on the buoly is removed for the chamber to rise and drain itse f.

The sea-cocks M may be adjustable simultaneously or individually to determine the appropriate rate of leak and reserve buoyancy, as may be the air vents 15 for the same purpose.

Additionally or alternatively the air vents It: may be in communication with air pumping and escape means, in which case the buoyancy of the chamber 2 may be varied at all times by such means independently of the degree of submersion of the buoy. In such a case the construction of the chamber 2 may be simplified'and the sea-cock or cocks [4 need not necessarily be above the normal water line, so that a greater range of buoyancy is obtainable. Further, in cases where the buoyancy is so positively adjustable at all times it is possible to maintain buoys at their minimum buoyancy during the period when a ship is tied up, and when subsequently casting ofi to restore the buoyancy to the buoys simultaneously or selectively to push a part or the whole of the ship away from the berth to facilitate its departure.

Figure 6 shows the manner in which three, say, of the buoys as above described may be moored in general alignment so as to take the lateral thrusts of ships of various sizes Without allowing a swinging movement thereof.

In the arrangement of Figures 7 and 8 the fender l is of considerable length and carries an extensive, and preferably flexible or articulated, platform structure [5 floatingly supported by tanks I! incorporated therein. A plurality of buoyancy chambers 2 are spaced from the platform 55 by structures 3 and the mooring arrangements are similar in principle to those described in connection with Figures 1 to 6.

The composite buoy thus obtained operates in the same way as those previously described, with the added advantage that when the ship has been berthed the platform iii may be used to facilitate the embarkation or landing of passengers and/or cargo.

Figures 9 and 10 illustrate diagrammatically the manner in which a modified form of bumper-buoy according to the invention may be pivoted to a fixed or floating landing stage, pier or the like it about an axis l9 parallel and adjacent to its nose or fender part i and the edge of the landing stage. It will be apparent that when the lateral thrust of a ships side is applied to the fender I the buoyancy chamber 2 will be progressively submerged as in the previous cases, and as indicated in dotted lines in Figure 9. The chamber 2 may of course be adapted to have its buoyancy varied or controlled as previously described.

Figure 11 shows how a similar form of bumperbuoy may be housed in a suitable recess or bay 20 in a solid sea wall, quay or jetty. The bay 20 may be roofed over for safety. as indicated at 2|.

In the modification illustrated by Figures 12 and 13 the bumper-buoy comprises a bank of superposed horizontal cylindrical buoyancy chambers 22 projecting laterally from a quay wall and provided with fender portions 23 along their seaward faces. Each cylindrical chamber 22 is pivoted about a horizontal axis 24 close underneath it, and it will be seen that under the lateral thrust of a ships side the chambers move inwards into a recess or bay 25 in the quay and at the same time are depressed or increasingly submerged. Vertical connecting rods 26 are provided at the ends of the chambers to ensure that the lateral thrust is distributed equally between all the chambers. If desired, however, the bank shown could be replaced by a single cylindrical chamber of suitable size and buoyancy.

It is to be noted that where bumper-buoys according to the invention are mounted on or anchored to floating structures they will have the desirable feature of operating independently of wide variations in the general water level due to tidal or other conditions.

What I claim and desire to secure by Letters Patent of the United States is:

l. A shock-absorbing marine berthing device, comprising in combination a normally floating buoyancy member and a floating fender member rigidly spaced therefrom, and means forming a common submerged horizontal axis substantially in the vertical plane of said fender member and about which said members are each pivoted, so

that horizontal displacement of said fender member causes, and is resiliently opposed by, a sharp depression of said buoyancy member.

2. A shock-absorbing marine berthing device comprising in combination a buoyancy member and a fender member carried thereby, and means forming a horizontal underlying axis about which said members are each pivoted, so that lateral displacement of said fender member causes, and is resiliently opposed by, depression of said buoyancy member and said buoyancy member being perforated for the gradual admission of water to alter its buoyancy.

3. A shock-absorbing marine berthing device according to claim 2, and wherein said buoyancy member is soperforated immediately above an internal transverse partition forming the floor of a floodable portion thereof, and is sealed below said partition to retain sufiicient reserve buoyancy to rise and drain itself when free to do so.

ERNEST JAMES BUCKTON. 

